I played quite a bit and I found a bug. Once in the cave, the buttons in the lower part can't be clicked (so you need to Esc to exit). Also, that gaze linking puzzle... I don't get it. :)
95 days ago(+1)
Thanks for the heads up on this bug, it has been fixed.
As for the gaze linking puzzle, start with the portrait at the top-center, and aim for the eyes :)